Cutting machine



March 28, 1944. J. ANDERSON I CUTTING MACHINE Filed Aug. 26, 1941 eSheets-Sheet 1 N m R Y om E mm m EA 0 M n n? 84/ A 1 E WM/1flli. \wmmmll/ Mi i rlLq MIIU J m J m In.

March 28, 1944. L; ANDERSON 2,345,314

CUTTING MACHINE Filed Aug. 26, 1941 6 Sheets-Sheet 2 INVENTOR JAMESL.ANDERSON BY ATTORNEY March 8, 1944 J. L. ANDERSON CUTTING MACHINEFiled Aug. 26, 1941 6 Sheets-Sheet 3 INVENTOR JAMES L. ANDERSON BY XATTORNEY M Q, U

March J. L. ANDERSON ,345,3

CUTTING MACHINE Filed Aug. 26, 194i 6 Sheets-Sheet 4 INVENTdR 1 JAMES L.ANDERSON ATTORN EY Maid 28, 1944.

Filed Aug. 26, 1941 6 Sheets-Sheet 5 INVENTOR JAMES L. ANDER SON BY%I IY ATTORNEY .1. 1.. ANDERSON 2,345,314

CUTTING MACHINE Filed Aug. 26, 1941 March 28, 1944.

6 Sheets-Sheet e INVENTOR JAMES L. ANDERSON JIM ATTORNEY Patented Mar.28, 1944 UNITED STATES PATENT OFFICE CUTTING MACHINE James L. Anderson,Closter, N. J., assignor to Air 2 Reduction Company, Incorporated, NewYork, N. Y., a corporation of New York Application August 26, 1941,Serial No. 408,320 I 22 Claims. (01. 26623) i This invention relates tocutting machines, and more especially to machines for cutting hot slabs,though in its broadest aspects the invention is not limited to apparatusfor that purpose.

It is an object of the invention to provide improved apparatus forlocating a cutting torch in position to start a cut at the edge of awork piece, and for then moving the torch progressively across the pieceto be cut. Slabs that move along a conveyer are not always centered onthe conveyer, and they are of different widths. This invention includesa carriage that moves out over the conveyer table until an abutment onthe carriage strikes the side of the slab. The cutting apparatus isconnected with the carriage in such relation that a cutting torch is inposition to start a cut from one end of the slab when the abutment ofthe carriage comes against the side of the slab. In this way the torchis quickly positioned regardless of the width of the slab or the amountthat the slab may be to one side or the other of the center of theconveyer or mill table. Another object of the invention is to provideautomatic means for positioning two torches at opposite sides of a slabor other work piece and then moving the torches toward one another alongan intended line of out. In accordance with one feature of the inventiontwo carriages are moved together by means that reacts against both sothat when either carriage comes against the side of a slab, the othercarriage continues to move until it too contacts with the slab.

Other features of the invention relate to automatic control of the twotorches that move toward one another from opposite sides of the workpiece. The automatic control obtains a stoppage and reversal of onetorch when it approaches within a given distance of the second torch anda delayed reversal of the second torch which occurs only after thattorch has continued its out up to the point where the first torchstopped.

One advantage of the two torches that cut simultaneously is that thetime required to cut a slab is reduced almost 50% and the cuttingoperation thereby causes less delay in the passage of the slabs alongthe conveyer and is less likely to be a bottleneck in the millproduction.

Other objects, features and advantages of the invention will appear orbe pointed out as the specification proceeds.

In the accompanying drawings, forming part hereof:

Fig. 1 is a top plan view of a slab cutting machine embodying theinvention.

Fig. 2 is an enlarged side elevationsh'owing the left side of themachine of Fig. 1.

Fig. 3 is an enlarged sectional view taken on the line 33 of Fig. 1.

Fig. 4 is a sectional view on the line 44 of Fig. 3.

Fig. 5 is an enlarged front elevation of the automatic control means forstopping and reversing the movement of the torches at the end of acutting operation. r I

Fig. 6 is a view similar to Fig. 5 but showing the parts in differentpositions.

Fig.7 is a top plan view of the structure shown in Fig. 5. v

Fig. 8 is a sectional view on the line 8-8 of Figs. 5 and 9.

Fig. 9 is a rear elevation of the control means shown in Fig. 5.

The cutting machine shown in Fig, 1 includes a main carriage ID withfour flanged wheels II that stably support the carriage and run alongrails l2 on opposite sides of a conveyer comprising rollers l5. Theupper framework of the main carriage straddles the conveyer and hasenough clearance to permit a metal body comprising a slab 14, or otherwork piece, to pass under this upper framework.

The main carriage includes fixed side frames I6 rigidly connected by across beam ll. These side frames l6 are fixed with respect to the axlesof the wheels I l, and only move when the entire carriage travels alongthe rails [2.

The main carriage has a vertically movable portion comprising movableside frames IS with arcuate bearings 20 that are vertically movable onguides 21 at the forward ends of the fixed side frames I6. Thesevertically movable side frames l9 are connected to form a rigidcomposite frame structure by tubes 23, 24 and a gauge bar 25.

There are two tubes 23, one below the other as shown in Fig. 3, andthere are two tubes 24. These tubes 23, 24 serve as guide rails forgrooved wheels 26 of a torch carriage 28. The wheels 26 run on the lowertubes 23 and 24, and there is small clearance between the upper tubes23, 24 and the tops of the wheels 26. These upper tubes 23 and 24 serveas guard rails to prevent the wheels 26 from being displaced upward fromthe lower tubes.

A torch holder 30 attached to the carriage 28 supports a torch 3| inposition to direct a cutting jet against the slab I4. During the cuttingoperation the vertically movable portion of the main carriage is in alowered position and supported by the gauge bar 25 that rests directlyon the slab i l. The gauge bar has a scalloped bottom surface to reducethe transfer'of heat from the hot slab [4 to the metal of the gauge bar,

The vertically movable portion of the main carriage is raised andlowered by cylinder-andpiston motors 33 (Fig. l). The cylinders of thesemotors are connected to the fixed side frames i6 by brackets 34 in whichthe cylinders are held by pivots so that the motors can oscillate toallow for changes in the obliquity of their piston rods. Themotion-transmitting mechanism by which the motors 33 raise and lower thevertically movable side fram-es 19 comprises a simple link mechanismsuch as shown in Fig. 2. The piston rod 35 of the motor 33 is connectedby apivot 36 to a downwardly extending arm of a bell crank 31 that rocksabout a fulcrum 38 extending out'from the fixed side frame'l6. Aforwardly extending arm of the bell crank 31 is connected with thevertically movable frame l9 by a short link 39. Movement of the pistonrod 35 to the right in Fig. 2 rocksthe bell crank 31 counterclockwiseand causes the link 39' to pull the side frame l9 upward along the guide2|. Operation of the motor 33 in the reverse direction causes thevertically movable portion of the main carriage to move downward untilthe gauge bar 25 rests on the work to becut. Each of the motors 33, onthe opposite sides of the machine, operates similar linlc mechanism. Theweight of the vertically movable side frames 19 and the structureconnected to them is counterbalanced by weights 4e that are elampedtoand adjustable along a lever 40', the forward end of which is connectedwith the vertically movable side frame I9 by a link 46 There is asimilar counterbalance on each side of the machine, and the levers 46'are supported by a fulcrum shaft 4| attached to the fixed frames l6.

A screw carriage. (Fig. 1) is associated with the torch carriage 28.This screw carriage has grooved wheels 43, similar to the wheels 26 ofthe torch carriage 28, and that run on the tubes 23, 24 as rails. A leadscrew 44 is supported at one end in bearings in the screw carriage. Thislead screw can rotate in the bearings, but is held against longitudinalmovement so that it moves longitudinally as a unit with the carriage 42when the carriage travels along the tubes 23, 24.

The lead screw 44 threads through the body of the torch carriage 28 sothat rotation of the lead screw in one direction thrusts the torchcarriage 28 along the tubes 23, 24 away from the screw carriage42,-whereas rotation in the other direction moves these carriages 28 and42 closer together.

At the oppositeileft) side of the machine there is a torch carriage 45and a screw carriage 46 similar to the corresponding carriages 28 and42, respectively, at the right side of the machine but with certainstructural reversals necessary for use on the opposite side of thecutting machine.

The screw carriages 42 and 46, at the opposite sides of the machine, areconnected together by a cylinder-and-piston motor 48 comprising acylinder 49 that is-secured near one end to the screw carriage 42 and apiston rod 56 that is fastened to the screw carriage 46.

The motor 48 is double acting. Admission of working fluid, such as air,to the right end of the cylinder'49 causes the screw carriages 42 and 45to be moved away from one another. Admission of working fluid to theother end of the cylinder 49 moves the screw carriages 42 and 46 closertogether.

The screw carriage 42 has a downwardly and rearwardly extending bumperor abutment 52 (Fig. 4) that strikes against the side of the slab [4 toprevent further inward movement of the screw carriage 42. There is asimilar bumper or abutment 53 on the screw carriage 45. One advantage ofhaving the cylinder 49 connected to one of the screw carriages and thepiston rod 55 connected to the other screw carriage is that the motorcontinues to move the other. carriage regardless of how soon theabutment of the first carriage strikes the side of the slab. The two Iscrew carriages 42 and 45 are thus moved into positions with theirabutments 52 and 53 against the sides of the slab l4 regardless of howmuch off-center the slab may be on the mill table or conveyen,

Pressure of working fluid in the motor 48 holds the abutments againstthe side of the-slab. Thus the screw carriages 42 and 46 serve aspositioning carriages for initially locating the torch carriages 28 and45.

As the screw carriages 42, 46 are moved toward one another by the motor48, the torch carriages 28 and 45 move with the screw carriages 42, 46.When the abutments 52, 53 are against the sides of the slab I4, and thetorch carriages E8 and 45 are as close as possible to their re-'spective screw carriages 42 and 46, the torches on the carriages 28 and45 are in position to start cuts on the slab I4 at opposite sides of theslab.

The screw 44 is rotated, by driving mechanism that will be described, tomove the torch carriage 2B inward, and traverse the torch over the slabduring the cutting operation. At the same time a lead screw 55,supported by the screw carriage 45, is rotated to drive the torchcarriage,

45 inward and move its torch over the slab.

The lead screws 44 and 55 are at different levels so that the inner endof one can extend under the other when operating on narrow slabs thatrequire the screw carriages to be spaced by a distance less than thecombined lengths of the lead screws 44, 55. There is an opening 56 inthe torch carriage 28 in line with the screw 55 and a similar alinedopening 55 in the screw carriage 42 into which the lead screw 55 extendswhen the screw carriages 42 and 46 are close together. There are similaropenings in the left-hand carriages 45 and 46 for the lead screw 44.

A gear 51 keyed to the bearing end of the lead screw 44 is driven by agear 58 (Fig. 3) that is enclosed on both sides by the screw carriage 42that slides along a shaft 59. Keys in the gear 58 slide in grooves 60 inthe shaft 59 so that the gear 58 rotates with the shaft 59 but can atthe same time move lengthwise along the shaft 59 when the screw carriage42 travels along the rails 23, 24.

The lead screw 55 (Fig. 4) has a gear Bl keyed to the bearing end of thescrew, and this gear is driven from a shaft 62 in the same manner as thegear 51 of the lead screw 44 is driven from the lower drive shaft 59.The lower shaft 59 is driven by an electric motor 64 (Fig. 1) throughreduction gearing, and the upper shaft 62 is driven by a motor 65. Therate at which the cutting torches 3| move across the slab depends uponthespeed of the motors 64 and 65, and each of these motors is equippedwith an adjustable centrifugal governor 66.

The governor of the motor 64 has an adjusting knob 61 that is turned inone direction or Another square rod 88 connects the left-hand the otherto increase or decrease the speed at which the governor becomeseffective. The knob 66 is rotated by a motor 68 through reductiongearing. The adjusting knob of the governor for the motor 65 isconnected with the knob 61 by a belt 69 so that both of the governorsare adjusted in unison by the motor '68.

Since the torches 3| of both torch carriages out along the same straightline; limit switches are provided for automatically stopping the torchcarriages before the torches strike one another. The limit switches areconstructed and arranged so that they cause the left-hand torch carriage45' to stop and reverse while the righthand torch carriage 28 continuesto move inward. The switch-operating mechanism is adjusted so that thetorch carriage 28 will continue to move until the out made by theright-hand torch 3| joins the cut made by the torch on the left-handtorch carriage, and thereby completes the severing of the slab. Theright-hand torch carriage 28 then reverses and returns to its startingposition. The apparatus for effecting this operation is shown in Figs.5-9.

Referring first to Fig. 5, a switch-box support is a sliding fit on theupper tube 24. A key that slides in a slot 12 in the upper tube 24prevents the switch-box support 18 from turning on the tube. A limitswitch-box 13 (Fig. 7) is connected to the back of the support 10. Thebox 13 and support Ill may be made in one piece.

A limit switch operator I4 is a sliding fit on the upper tube 24 and isheld against rotation on the tube by a key that slides in the slot 12. Alatch is supported from the front of the operator 14 by a pivot 18 (Fig.6). A spring I! is connected at its lower end to the latch 15 and isconnected at its upper end to a stud 18 that extends from the switchoperator M. This spring 11 urges the latch 15 either clockwise orcounterclockwise depending upon which side of the center of the pivot 16the spring 11 passes for the particular position in which the latch 15happens to be.

A pin 80 extends from the back face of the latch 15 and into a slot inthe top end of a crank 8| that operates an eccentric brake 32. When thelatch 15 is in the position shown in Fig. 6, the spring 71 urges thelatch to move counterclockwise around the pivot 15. With'the latch 15 inthis position the eccentric brake 82 is turned into a position in whichit clamps against the bottom side of the upper tube 24. Any furthermovement of the latch 15 in a counterclockwise direction moves the pin88 tothe right,

' rocks the crank 8! and eccentric brake 82 clockwise and causes theeccentric brake to clamp more firmly against the tube 24.

During most of the operation of the apparatus the limit switch operatorM is up against the end of the switch-box support 19, and is held insuch position by a latch plate 84 that is secured to the support 10, andhas a hook end with which a. complementary portion of the latch 15engages, as shown in Fig. 5. The limit-switch support 18 is connectedwith the right-hand torch carriage 28 by a square rod 85.Semicylindrical grooves 85 in the rod 85 register with similar groovesin the support 10 to provide openings for a clamping bolt 8! thatfastens the rod 85 to the'support 18. The distance of the support 10from the torch carriage can be adjusted by bringing different grooves 86of the rod 85 into register with other ones of the grooves of the limitswitch support 70.

torch carriage with a tube traveler 89 that slides on the lowertube 24.The traveler 89 is adjustably connected with the square rod 88 by aclamping screw 90 in the same manner as the clamping screw 81 fastensrod 85 to the limit switch support 18.

An abutment 92 is secured to the rod 88 in position to strike the lowerend of the latch 15 whenever the two torches are moved by theircarriages to within about two inches of one another.

Since the limit switch support 18 and rod 85 move as a unit with theright-hand torch carriage 28, and the abutment 92 and rod 88 move as aunit with the left-hand torch carriage 45, the parts will always occupythe same positions with respect to each other, when the torches are twoinches apart, regardless of how much off-center the slab may be on themill table or conveyer.

The limit switch operator I4 is latched to the imit switch support 18and moves to the left in Fig. 5, and the abutment 92 moves to the right,during each cutting operation, until the abutment strikes the lower endof the latch 15, rocks the latch counterclockwise out of engagement withthe latch plate 84, and stops the travel of the limit switch operator 14along the tube 24. The limit switch support 18 continues to'move towardthe left and pulls away from the switch operator 14 as indicated in Fig.6. It is this relative movement of the limit switch support 18 and thelimit switch operator 14 that causes the operation of the limit switchesthat are carried by the support Ill. As the abutment 92 moves the latch15 further in a counterclockwise direction, it causes the pin 80 to movethe crank 8| and clamp the eccentric brake 82 firmly against the tube24.

There are two limit switches 94 and 95 (Fig. 9) in the switch box 13carried by the limit switch support 10. A rod 95 extends through thelimit switch operator l4 and through an opening in the, wall of theswitch box 13. This rod is threaded throughout at least a portion of itslength and is held in a fixed position with respect to the limit switchoperator by nuts 98 threaded on the rod 95 and clamping against oppositesides of the limit switch operator. These nuts provide a means foradjusting the position of the rod 96 lengthwise with respect to thelimit switch operator 14.

Both of the limit switches 84 and 95 are single pole, double throw, snapswitches with a bias toward the left when viewed from the back as inFig. 9. The positions of the nuts 98 are adjusted so that the rod 96contacts with the button of the limit switch 95 and holds the pole ofthat limit switch against the right-hand contact of the 85. Thisoperation of the switch 95 causes the motor driving the left-hand torchcarriage to stop and reverse.

An upper rod I88 extends through the operator M and through the side ofthe switch box I3.

The rod 598 has a head l9! inside of the switchbox T3. The head it! ispinned on the rod- I and a spring Hi3, compressed between the head IBIand the wall of the switch box '13, holds the end of the rod I againstthe button of the limit switch 94. The spring I03 is stronger than thebias of the switch 94 and holds the pole of the switch 94 against theright-hand contact in Fig. 9; Whenever the pressure of the spring N33 isremoved from the button of switch 94, the bias of this switch shifts thepole over to the lefthand contact of the switch and causes the motorthat drives the right-hand torch carriage 23 to reverse.

There are two nuts I threaded on the end of the rod I00 remote from theswitch box 73. When the switch box I3 moves away from the operator I4far enough for the nuts IE5 to strike against the operator I4 thenfurther movement of the switch box I3 away from the operator I4 causesthe spring IE3 to be compressed and its pressure released from the upperlimit switch 94 so that the pole of this limit switch shifts overagainst its left-hand contact, as previously described.

Referring to Figs. 1 and 9, when the poles of the limit switches 94 and95 are against the righthand contacts (in Fig. 9), and the motorcircuits are not opened by other switches, both of the motors 64 and 65operate and in directions that cause the torch carriages 28 and 45 tomove toward one another. Shifting of the pole of the lower limit switch95 over against the left-hand contact of that switch reverses thedirection of rotation of the motor E5 and causes the torch,

carriage 45 to reverse and move back toward the screw carriage 46.

Shifting of the pole of the upper limit switch 94 over against theleft-hand contact of that switch reverses the direction of rotation ofthe motor 64 and causes the torch carriage 28 to move away from thetorch carriage 45. The nuts I05 on the rod I00 are adjusted to such aposition that the torch carriage 28 does not reverse until its torch 3|has out far enough to meet the cut made by the torch of the othercarriage.

Limit switches for stopping the motors 64 and 65 when the torchcarriages 28 and 45 have been moved back against the screw carriages 42and 26 are not illustrated. Such switches, as well as starting switchesand the motor circuits, are well understood and a description of them isnot necessary for a full understanding of this invention. Variouschanges and modifications can be made in the illustrated embodiment ofthe invention, and some features can be used without others withoutdeparting from the invention as defined in the claims.

I claim:

1. Apparatus for cutting a metal body, said apparatus including acarriage, supporting means along which the carriage moves, an abutmenton the carriage in position to contact with the side of the body to becut, a torch holder moved by said carriage into position to start a cutat the edge of the metal body when the abutment is against the side ofthe body, supporting means on which the torch holder is movable, andmeans on the carriage for causing the torch holder to move on itssupporting means and with respect to the carriage along a projected lineof cut.

2. A torch cutting machine including a first carriage, supporting meansalong which said carriage moves, means for positioning the firstcarriage including an abutment on said carriage for contact with a sideof a metal body that is to be cut, a second carriage connected with thefirst carriage and movable as a unit with the first carriage whileoriginally positioning the first carriage, a torch holder on the secondcarriage for positioning a torch at the edge of a metal body in positionto start the cut when said abutment is against the side of the metalbody and the carriages are in a predetermined relation with one another,and means on the first carriage for moving the second carriage withrespect to thefirst carriage to traverse a torch across the metal bodyalong the line to be cut. I

3. Torch cutting apparatus including two wheeled carriages, guide meanson which the wheels run, a torch holder on one of the carriages, meansconnecting the torch holder carriage and the other carriage for movementas a unit when originally positioning the torch holder to locate a torchcarried by the holder in position to start a cut, an abutment forstopping said other carriage in a given position, and means for causingfurther movement of the torch-holder carriage independently of saidother carriage to move a torch along the desired line of cut.

4. In a machine for cutting metal bodies, po-

sitioning carriages located on opposite sides of a body to be cut,supporting means along which the carriages move toward and from oneanother, an abutment on each carriage in position to strike against themetal body and limit the movement of the carriages toward one another, atorch holder connected with each carriage, supporting means on whicheach torch holder is movable with respect to its carriage, and mechanismfor moving the torch holders across the metal body independently of saidcarriages after the abutments have stopped further movement of saidcarriages.

5. Apparatus for cutting a metal body including in combinationsupporting means, two carriages movable toward and from one another andlocated at opposite sides of the metal body to be cut, a holderconnected with each carriage'for supporting a torch, an abutment on eachcarriage in position to strike against a side of the metal body when thecarriage moves into a position that locates its associated torch inposition to start a cut at one edge of the metal body, and

' power means for moving the carriages on opposite sides of the bodytoward each other and against the sides of the body even though the bodyis not centered between the carriages, said power means including avariable-length connection between the carriages and means for causingvariations in said length.

6. In a cutting machine including torch supports that move torchesacross a work piece from opposite sides, an additional device for movingthe torch supports into an original starting position, said devicecomprising a cylinder-and-pis-' ton motor with the cylinder connectedwith the torch support on one side of the work piece, and the pistonconnected with the torch support on the other side of the work piece.

'7. Torch cutting apparatus comprising a conveyer for supporting a metalbody that is to be cut, a track comprising tubular members extendingacross the conveyer above the-metal body and transversely of thedirection of movement of the metal body along the conveyor and for adistance substantially greater than the width of the metal body to becut, a first carriage movable along the track from one end, atorch-supporting carriage movable along the track in front of the firstcarriage, a lead screw connecting the first carriage and thetorch-supporting carriage for causing the carriage to move along thetrack as a unit when the lead screw has no angular movement, mechanismfor rotating the lead screw to cause the torch-supporting carriage tomove forward with the carriages prior to starting a cut, similarcarriages movable along the track from the other end, and acylinder-and-piston fluid motor with its cylinder connected to saidfirst carriage and having a piston rod connected with the correspondingcarriage at the other end of the track.

8. A torch cutting machine including two carriages positioned one aheadof the other and independently supported, a torch holder on the forwardcarriage, a lead screw connecting the carriages for movement as a unitwhile the lead screw has no angular movement, and means for rotating thelead screw to cause the forward carriage to move with respect to therearward carriage and traverse a torch along a desired line of cut.

9. A torch cutting machine including two positioning carriages disposedin positions on opposite sides of a metal body to be cut,carriagesupporting means on which the carriages are movable toward andfrom one another for initially positioning cutting torches at oppositeedges of the metal body, a torch-holder carriage for each of saidpositioning carriages, said torch-holder carriages being movable alongthe carriage-supporting means, and connections between each of thepositioning carriages andits torch-holder carriage, said connectionsbeing constructed and ar- 1 ranged to cause the connected carriages tomove into starting position as a unit, but operable to ,move the torchholder carriage independently of the positioning carriage during acutting operation.

10. A torch cutting machine including two psitic-ning carriages disposedin positions on opposite sides of a metal body to be cut,carriagesupporting means on which the carriages are movable toward andfrom one another for initially positioning cutting torches at oppositeedges of the metal body, a torch-holder carriage for each of saidpositioning carriages, said torch-holder carriages being movable alongthe carriage-supporting means, and connections extending from each ofthe positioning carriages to its torchholder carriage, and beyond saidtorch-holder carriage on the side toward the carriages at the other sideof the work piece, said connections being operable to shift thetorch-holder carriages to-'- ward and from one another independently ofthe positioning carriages, and being located at different levels so thatone can overlie the other when the positioning carriages are closetogether.

11. A torch cutting machine including guides that extend across andbeyond both sides of a metal body to be cut, a wheeled carriage movablealong the guides from one side of the metal body, a lead screw supportedby the carriage, another wheeled carriage on the guide and through whichthe lead screw threads so that both carriages move as a unit when thescrew has no rotary movement but have relative movement when the screwrotates, said screw extending parallel with the guides and for asubstantial distance beyond the carriage through which it threads, 2,torch-holder on the carriage through which the screw threads, gears onthe screw-supporting carriage including a driven gear secured to one endof the screw and a driving gear in mesh with said driven gear, a driveshaft of non-circular section extending parallel with the guides andthrough the driving gear which is a sliding fit on said drive shaft,-asecond screw-supporting carriage and a second torchholder carriage foroperation along the guides from the other side of the metal body, thesesecond carriages being similar to the first-mentioned carriages buthavinga lead screw at a different level from the lead screw of the firstcarriages so that one lead screw can overlie theother, and anindependent drive shaftv for the screw associated with the secondcarriages, the carriages for each side of the Work piecehavin'gclearance openings in alinement with the lead screw of the othercarriages.

12. A torch cutting machine including a frame, vertically extendingguides on which said frame is movable into and out of contact with ametal body to be cut, a track on the. frame, a torch carriage movablealong the track, and a holder on the carriage for positioning a torchincutting relation to the metal body when said frame is in a loweredposition and resting on the metal body to be cut.

13. .A torch cutting machine comprising a main carriage that straddles ametal body that is to be cut, supporting means along which the carriageis movable longitudinally of the work piece, said main carriageincluding a frame that extends transversely across the work piece and ismovable with respect to theremainder of the carriage up and down intoand out of contact with the top surface of the metal body, a track onthe frame, a

-torch carriage movable along the track, and a holder on the carriagefor positioning a torch in cutting relation to the metal; body when saidframe is in a lowered position and restingon the metal body to be cut.

, 14. A torch cutting machine comprising a mai carriage that straddles ametal body that is to be cut, supporting means along which the carriageis movable longitudinally of the Work piece, said main carriageincluding a frame and having vertically extending guides on which saidframe is movable toward and from the top of the metal body, motor meanson that part of the carriage on which the guides are located, and linkmeans connected with the movable fram and. operated by said motor meansto cause the frame to move up and down on said guides, said frameincluding a gauge bar that contacts with the metal body and supports theframe from said body when the frame is in its lowered position, paralleltubes forming a part of the frame and extending transversely of themetal body, a torch carriage with grooved wheels that fit the tubes andrun on the tubes as track, and a torch holder on the carriage.

15. A torch cutting machine, including a guide, torch carriages movablealong the guide from opposite ends of said guide for traversing torchesalong different parts of a projected cut, motor means for moving thetorch carriages, and automatic control apparatus for stopping one of thetorch carriages when it approaches within a given distance of the other.

16. A cutting machine including a guide, torch carriages movable alongthe guide from opposite ends of said guide for traversing torches alongdifferent parts of a projected cut, reversible, power operated, drivingmeans for moving the torch carriages, and automatic control apparatusfor reversing the operation of the driving means of one of the torchcarriages when it approaches within a given distance of the other.

17. A torch cutting machine including two torch carriages movablesimultaneously across a work piece and toward one another from oppositesides, means for supporting a torch from each of said carriages with thetorches disposed to make different parts of a straight line cut, aseparate motor for operating each of the carriages, and automaticcontrol means for the motors operated by displacement of the carriages.

18. A torch cutting machine including two torch carriages, supportsalong which the carriages are posite edges of a work piece during acutting operation, operating mechanism for the torch carria'ges, andautomatic control devices that stop and reverse the operating mechanismof one torch carriage and subsequently stop and reverse the operatingmechanism of the othertorch carriage.

20. Torch cutting apparatus including two torch carriages that movetoward one another from opposite edges "of a work piece during a cuttingoperation, a separate motor for operating each of the carriages,motion-transmitting, means between each motor and the carriage operatedby that motor, a limit switch for each motor, and

limit switch-operating means movable with at least one of the carriagesand including a lostmotion connection that causes one of the limitswitches to be operated ahead of the other.

21. A torch cutting machine including a track, two torch carriagesmovabl toward one another along the track to traverse cutting torchesacross ,a metal body from opposite edges of the body, a

separate motor for operating each of the carriages, motion-transmittingmeans between each motor and the carriage operated by that motor, alimit. switch for each motor for stopping and reversing the motor, saidlimit switches being connected to and movable as a unit With one of thetorch carriages, and an operator for each switch, said operators beingconnected to the other torch carriage, and one of said operators havinga lostmotion connection that causes one of the limit switches to beoperated ahead of the other.

22. Torch cutting apparatus including a track, two torch carriagesmovable toward and from one another along the track to move cuttingtorches inward across a work piece from opposite edges and then back totheir original positions after completing the cut, a separate motor foroperating each of the carriages, motion-transmitting connections betweeneach motor and the carriage that is operated by that motor, a controlswitch for each motor, each switch having a bias toward a position thatcauses the motor to operate in the direction that moves the torchcarriages closer together, but being operable into a position thatcauses the motor to reverse, a support by which both of the limitswitches are carried, a guide along which the limit switch supportmoves, a connection between the limit switch support and one of thetorch carriages'for causing the support to move as a unit with thatcarriage, a switch operator movable along the guide, a latch forconnecting the switch operator to the limit switch support, a brake onthe switch operator for resisting movement of the switch operator alongthe guide, and an abutment member connected to and movable as a unitwith the other tech carriage into position to release said latch andapply said brake when the torch carriages approach within a givendistance of one another.

JAMES L. ANDERSON.

